Serial downloader
You can use the serial downloader boot mode for device recovery. The serial downloader allows you to download a program image to the chip through a USB or UART serial connection. When any of the standard boot modes is selected but the booting process doesn’t succeed (for instance due to wrong booting device or corrupted images) the CPU automatically jumps to the serial downloader boot mode.

If SDP eFuses is burned, how can device be recovered via USB since it's managed by SDP ?